Top 10 Basic 3D Slicer Settings you need to familiarize
You may be aware of the role of a 3D slicer in 3D printing by now. But for those of you who are new to this, a 3D slicer is a software that slices a 3D model into layers and convert them to GCode so the 3D printer can understand.
Being an integral part of the 3D Printing work flow, the 3D slicer settings can directly relate to a print success or a failure.
There are many 3D Slicers out there, but we will be focusing on the most popular and free 3D slicers – Ultimaker Cura and PrusaSlicer. So let’s jump right in and see the 10 basic settings that are common to any 3D Slicer and we’ll see how to modify them to print objects with amazing quality everytime.
There are a lot of settings that can affect the quality of the print, but some of it could be a little overwhelming for a new user.
Let’s take a look at the Cura Interface first.
This is the basic interface of Cura 4.8.0. As you can see, there aren’t a lot of settings to work with. Clicking on the custom button will reveal a huge list of settings, but let’s just enable the necessary ones so you don’t get confused. First click on the ‘more options’ icon and then select ‘Basic’.
Next, click on the ‘more options’ icon and then select ‘Manage Setting Visibility’. From the pop-up window, search for the following settings and enable them by checking the corresponding box:
- Z Seam Alignment and Z Seam Position
- Print Speed and Travel Speed
- Retraction Speed and Retraction Distance
- Support Structure
- Support Density
- Support Z Distance
- Enable Support Interface
- Support Interface pattern
I know some of these might seem gibberish right now, but you’ll understand what it is soon enough.
Moving on to the PrusaSlicer 2.3.0, during the initial configuration wizard, select ‘Advanced mode’ under the View Mode settings and all the necessary settings will be visible.
Table of Contents
Layer height can be found under the Quality tab in Cura and in PrusaSlicer, under the Print Settings -> Layers and Perimeters.
Layer height is, as the name suggests, the height of each layer of the 3D model. Layer height affects the printed object in many ways. The higher the Layer Height, the lower the resolution. If you want to print models with fine details, then it is best you choose a small layer height. With smaller layer height, the surface of the print looks smoother and the individual layers are practically invisible. But you also need to keep in mind that as you reduce the layer height, the print time increases as a result of the increased number of layers that constitute the model.
For applications like prototyping, you could do with thicker layers as fine details might not be in consideration. Additionally, prototyping with a larger layer height increases the bonding between each layer hence increasing the strength of the printed object. It also reduces the print time considerably.
Although you can play around with the layer height, the nozzle size limits the maximum and minimum layer height that can be used. The layer height should be within 80% the size of the nozzle. The recommended settings for different nozzle sizes are given below:
Table 1: Recommended Layer heights for different Nozzle Sizes
Shell is the outer perimeter of the 3d printed object. Shell thickness indicates the thickness of that perimeter. When the shell thickness is set to a higher number, it increases the number of layers that constitutes the outer walls and thereby increasing the strength of the object.
In Cura, 2 settings combine together to form the Shell – Wall Thickness and Top/Bottom thickness.
In PrusaSlicer, the shell settings are divided into 2 as well – Vertical Shells and Horizontal Shells
Wall thickness/Vertical Shells determines the number of layers surrounding the prints.
Top/Bottom Thickness/Horizontal Shells determines the number of solid layers at the very beginning and the very end of the print.
In addition to strength, increasing the Shell thickness can also aide in making the object water-tight.
Retraction simply means the filament needs to be pulled back into the hotend when the print head is traveling from one position to another in order to avoid the filament oozing out of the nozzle and leaving tiny webs of filament along the way.
Retraction settings varies under different circumstances – when using flexible materials like TPU or when using a Direct Drive extruder.
|Bowden Drive||Direct Drive|
|Retraction Length (mm)||8-16||0.6-2.8|
|Retraction Speed (mm/s)||35-50||25-40|
Table 2: Retraction Settings for Bowden and Direct Drive setups
While printing with TPU, due to its flexible nature, it is recommended to disable the retraction as it can get stuck in the extruder in case of a bowden setup.
On a direct drive setup, the retraction distance needs to be very low as compared to the bowden setup because the distance available for the filament to travel within the hotend is less.
In Cura, these settings can be found as Retraction Distance and Retraction Speed.
In PrusaSlicer, it is named as Retraction length and Retraction speed.
Print speed refers to the extrusion rate: the speed at which the print head moves in a span of time while extruding the filament. It also represents the speed at which layers are built while printing. The faster the print speed, the faster the object will be printed.
The print speed is determined by various factors: the model you’re printing, material used to print, the printer used and the layer height. However, 50 mm/s is a good place to start for beginners.
For designs with fine details, you’d get better details with slower speeds. For prototyping, you can play around with higher speeds, and find what works best for your 3D Printer.
Every filament available out there has it’s own temperature requirements. It is the temperature at which it melts in the hotend. Most materials have the optimum temperature called the Glass Transition Temperature: the temperature at which the filament turns from brittle glassy state into a rubbery state that can be extruded.
This temperature needs to be reached for a proper print quality. If the temperature is too low, then the filament will not melt adequately. This can cause it to stick to the inner part of the nozzle and eventually clogging up the nozzle.
It is also not a good idea to print at higher temperatures, especially with PLA. This can help prevent things like “heat creep”, where higher temperatures extend backwards from the nozzle. This causes the melt area to extend farther back as well, softening and melting the print material well before the nozzle end of the extruder. This can increase pressure in the hotend and cause your printer’s extruder motor to struggle and before you know it, your 3D printer nozzle is clogged. Plus it can also cause over-extrusion resulting in blobs and artifacts all over your prints.
In some rare cases, printing at too high temperatures – PLA and similar materials have known to crystallize in the nozzle.
The recommended printing temperatures for a particular material from a particular manufacturer will usually be mentioned on the package. You can also find the sweet spot by 3D printing a temperature tower.
A support structure is a temporary structure that holds up an overhanging portion of a 3D print so it stays in place while the printer is processing the rest of the object.
Overhangs are the unsupported sections of the print where they are longer than a 45 degree angle. Without supports the first layer of filament on an overhang would let the rest of the object collapse under its own weight in the absence of a base to build upon. The support structures help hold up the drooped part until it has been built out enough to build off of again.
Most 3D Slicers detect the overhangs automatically and enable supports so you don’t have to rack your brain analyzing the model to add supports.
In Cura, the settings that you need to take care of is the support type, support placement, Support Z distance and the support interface.
In PrusaSlicer, its the support placement, Contact Z Distance, interface layers.
- Support Type: In Cura, you have the option to choose between normal supports (that are just straight vertical blocks) and Tree supports that are irregularly shaped support structures that adjusts its shape according to the design.
- Support Placement: In the dropdown menu, in both Cura and PrusaSlicer, there are 2 types of placements to choose from – Touching build plate (support structures will be added only to those overhangs where the supports are able to lay on the build plate) and Everywhere (this could place a support structure on top of the printed surface as well).
- Support/Contact Z distance: The distance from the top of the support structure to the bottom of the object being printed. This gap provides clearance to remove the supports after the model is printed (exaggerated in the image).
Support Interface: The top and bottom layers of the support structure on which the actual model rests needs to be enabled and fine tuned to get better support undersides and to avoid a droopy underside.
Tweak these settings carefully on the 3D Slicer to find the right numbers for your 3D printer.
The infill in a 3D print is the proportion of material printed to effectively fill the object: it is expressed as a percentage, ranging from 100% (completely solid) to 0% (no infill at all).
The higher the fill density, the stronger the object will be because there is more material. For example, if 100% fill density is selected, there will be no empty space inside the object. The lower the fill density, the less material will be used, thus lowering cost. However, this also means that the printed product will have more empty space (hence lower strength).
The first layer of a print is the most important, and often the most difficult to get right. Skipping this step can lead to under-extrusion (if the nozzle is too close to the bed, not enough space for the filament to be deposited) or over-extrusion (if the nozzle is too far from the bed, the filament doesn’t stick to the bed). To make sure the prints don’t pop off halfway through, 3D Slicers have a built-in feature called an Adhesion Assistant.
Adhesion assistants are itty-bitty printed features designed to provide extra traction for parts as they’re being printed. This reduces the amount of force needed to keep your part from lifting off the build platform, which is especially important on first layers. Where possible, the 3D Slicer inserts built-in adhesion assistants into your models, but you can also add them manually if you need them. Adhesion assistant comes in 3 main forms:
- Skirt: A skirt is a thin outline around the object being printed that doesn’t really provide adhesion assistance. They act as a preview as to how your first layer will turn out and make any last minute changes to the bed levelling.
- Brim: The ‘brim’ is the set of lines that are attached to the outside of a print’s initial layer. These works by increasing the contact area between the print and the build platform, so that you need much less adhesives (like gluesticks or masking tape) or none at all, helping to prevent warping and improve adhesion and ensure that the print stays put.
- Raft: A raft is a set of sacrificial layers of filament that is laid down first on which your model is printed. The raft is created to help ensure that your print sticks to the bed and doesn’t warp upwards. If your print never touches the print bed, you don’t have to hold it down with adhesives. Yes, this will consume a bit more filament and take longer to print, but it may save you time and frustration to create better adhesion from the start.
In Cura, all these settings can be found under Bed Adhesion tab.
In PrusaSlicer, Skirt and Brim can be found under Skirt and Brim tab, while Raft can be found under Support Material.
The Extrusion Multiplier or Flow determines the number of steps the extruder motor turns per mm of material extruded. To make it a little simple for you, on most 3D slicers by default the Flow is set to 100%, which might push out 10 cm of filament, but if you set it to 50% only 5 cm of filament is pushed out.
By adjusting the flow multiplier in the 3D slicer, you can prevent under or over-extrusion without having to poke and prod into your firmware to modify the E-Steps (don’t worry about E-Steps right now, you still have a lot of time to learn about it).
In Cura, it can be found under Material as Flow and in PrusaSlicer it is named as Extrusion Multiplier.
There are two kinds of cooling you’ll need to deal with in your 3D printer: system-cooling and part-cooling. System-cooling is when fans are used to vent out the heat from the components like the Hotend or Mainboard. Part-cooling is the fans that cools and solidifies the filament as it comes out the nozzle.
A part-cooling fan helps make models that require overhangs print successfully. If not enough air is blown across the printed model, it can lean slightly until it hits the support material underneath and pushes back up into its original position. Although there is a built-in setting for cooling fan speed in your 3D slicer, you can manually adjust the fan speed to suit your material’s requirements.
When printing with PLA or PETG, be sure to keep cooling fans on. PLA produces the best results with proper cooling, whereas ABS on the other hand needs to cool very slowly, else it cracks as a result of shrinkage. So cooling fans needs to be turned off.
I know that some of the 3D slicer settings can be a little too immense, but trust me, you will get the hang of it as you start tweaking these settings.
If you have further questions about any of the 3D Slicer settings, Click here and book a meeting with me, I’ll be happy to answer your questions.
Be sure to check out Top 20+ Basic 3D Printing Terms to get yourself acquainted with some of the common 3D printing jargon.